Common smartphones, phablets, tablet computers, or comparable mobile electronic devices contain a front-facing camera placed on the front side of these mobile electronic devices. The front side of the mobile electronic devices also contains a display screen, using a display technology such as liquid-crystal display (LCD) or active-matrix organic light-emitting diode (AMOLED). The display screen may be oblong, with an aspect ratio of, for instance, 16:9, 2:1, 19.5:9, or 21:9.
The user may orient a mobile electronic device with an oblong display screen horizontally or vertically, which may result in operating modes known as “landscape mode” and “portrait mode,” respectively. The page orientation can also be described with the terms “landscape orientation” and “portrait orientation.” For example, a user may hold a smartphone horizontally (landscape mode) and may watch a video or movie displayed in full screen mode on the display screen.
The front-facing camera of a mobile electronic device may be used for video telephony or to take a self-portrait photograph, commonly known as a “selfie.” In recent years, the resolution on front-facing cameras has increased, and it is likely that the resolution will continue to increase in the future (e.g., from 8 megapixels to 13 megapixels) to enable the user to take “selfies” of the highest quality and record high-quality 4K videos. Therefore, in some embodiments, high-quality camera lenses for the front-facing camera and an undisturbed light path are essential.
Patent applications US2017/0123454 A1, US2017/0123453 A1, and US2017/0123452 A1, titled “Camera integrated into a display,” patent application US2017/0123575 A1, titled “Optical sensors disposed beneath the display of an electronic device,” patent application US2017/0124933 A1, titled “Mobile device with display overlaid with at least a light sensor,” patent applications US2017/0126979 A1 and US2017/0126937 A1, titled “Apparatus and method to maximize the display area of a mobile device,” and patent application US2015/0271392 A1, titled “System and method for coordinating image capture in a camera hidden behind a display device” suggest disposing the front-facing camera beneath the display screen of mobile electronic devices. However, depending on the display technology of the screen (e.g., LCD, OLED, Micro-LED, etc.), small, opaque, or semi-transparent structures that may be necessary for the operation of the display screen may blur or cloud the resulting picture of the front-facing camera because the light path must pass through the display screen. Furthermore, LCD panels often also require removing a diffuser layer to adapt them for use as transparent displays, and the polarizing filters of the LCD panels inherently limit the transmission efficiency of unpolarized light. This may reduce the light sensitivity of a front-facing camera located beneath the display screen, especially in low-light conditions.